1. Field of the Invention
The present invention relates to a joined body and a method for producing the joined body.
2. Description of the Related Art
A metal-ceramic joined body that includes a pair of electrodes, which are formed of a metal layer, on a surface of a porous ceramic honeycomb body is proposed (see, for example, Patent Literature 1). In this joined body, the metal layers contain Cr and Fe, and a diffusion layer formed of a metal silicide is disposed within a boundary between the honeycomb body and the metal layers and ensures reliability of an electrical junction in high-temperature environments. A joined body produced by compressing and firing a mixture of titanium dihydrate and silicon dioxide applied to a bonding region between a porous ceramic and stainless steel at 1200° C. or more is proposed (see, for example, Patent Literature 2). In this joined body, silicon dioxide is reduced by titanium dihydrate, and the porous ceramic is joined to the stainless steel with metallic titanium and metallic silicon. A joined body produced by joining a porous ceramic having pores filled with ceramic to a metal part with brazing filler containing an active metal is proposed (see, for example, Patent Literature 3). In this joined body, the porous ceramic is joined to the metal part with Ag—Cu eutectic. A joined body produced by joining a superalloy substrate for use in gas turbine blades to a ceramic thermal barrier layer formed of stabilized zirconia with a metal-ceramic graded composition structure layer containing Pt, Ir, Au, and the like is proposed (see, for example, Patent Literature 4). In this joined body, use of oxidation-resistant noble metals in the joining layer reduces the volume expansion of the metal due to oxidation and prevents the superalloy substrate from separating from the ceramic layer.